DigitalCameraReview.com
Lytro Sheds Some Light On Light Field Photography
by Grant Hatchimonji -  2/17/2012

Lytro, the company behind the revolutionary camera that allows users to adjust the focus of a photo after having taken it, brought a handful of reporters and photographers together here in Boston just last week to see what all the fuss was about. While getting to actually spend some hands-on time taking photos with the device was quite an experience, I was also shown just how much potential the future of light field photography holds.

Lytro camera

How does it work?

The secret behind the Lytro camera is something called light field technology. The camera has a small light field sensor inside of it, allowing it to capture a light field, which, as Lytro defines it, is "the amount of light traveling in every direction through every point in space." So whereas typical cameras can only capture the intensity and color of these rays of light (creating pixels), the Lytro camera also captures the vector direction of the rays of light.

"When a camera captures the direction in addition to the intensity and color of light, it's no longer capturing a pixel, it's capturing a ray," said marketing manager Gretchen Harding. As such, there aren't any existing terms from current photo technology to describe this camera's "resolution," so Lytro created its own unit of measure: the camera's light field sensor captures 11 megarays, or 11 million rays of light.

But the light field sensor isn't the only star of the show. There is also a small light field engine (version 1.0) found inside the Lytro camera, which takes over after the light rays are captured. The light field engine is powerful software that processes the light fields and subsequently creates interactive pictures in which users can adjust the focal points right on the camera. With all of the directional information from the light field, different focal points can be achieved by switching to the various locations in which any two of the light field's rays intersect.

Lytro camera front"It's all computational photography," explained Lytro's director of photography, Eric Cheng. He pointed out that there is also a more advanced version of the light field engine software found in the Lytro camera's bundled editing software, which is why users are also able to adjust their "living pictures" on their computers, too.

Getting to know the Lytro camera

The Lytro camera has a very unique build, as far as cameras go: It's a rectangular tube that's 4.41 inches long and 1.61 inches wide. It's a little heavier than you may think at first, weighing in at 7.55 ounces, but it's certainly nothing unmanageable. Thanks to a grippy rubber material coating the back third or so of the camera, the Lytro is actually quite comfortable to hold despite its edges and literally boxy form factor. Its design is also quite minimalist, with only two buttons -- power and shutter -- and a single micro USB port located on the underside of the unit.

In terms of the hardware, the light field sensor is CMOS, bound with a micro lens array and is roughly the size of a point and shoot camera's sensor, according to Cheng. It has a constant aperture with an f/2 lens and sports an 8x optical zoom that can be surprisingly noisy as the gears whir and click under the hood. I did appreciate how the zoom controls were implemented, however: there is a capacitive touch surface on the top of the camera (towards the back on the rubberized surface) that you simply drag your finger over left and right to zoom in and out. Unfortunately, the Lytro does not come equipped with a flash.

The back end of the Lytro is where users will find its 1.46-inch LCD touchscreen display, which serves as another form of input beyond the physical shutter button on the top of the camera. With the touchscreen, users can tap different areas to spot meter or select focal points (whether in real-time or playback mode) or access the camera's menus.

Lytro camera undersideThe actual interface of the camera is simple, due mostly to the fact that it doesn't have a ton of features. When in standby, nothing is on the HUD -- which is probably for the best given the limited real estate -- unless you're zooming, in which case a zoom bar pops up along the top edge of the screen. If you want to see the handful of options that the camera has available, you just swipe upwards from the bottom edge of the screen, which pulls up a small toolbar with three buttons: one for playback, one to view the remaining amount of storage, and one for switching to Creative Mode.

Creative Mode allows users to choose the center of the camera's refocusable range, so one instance in which this could be used is if you want the range to be on a person's face from their nose to their ears, but nowhere beyond that. All you need to do is tap the touchscreen to indicate where you want the range to be centered. Creative Mode can also let you shoot an "all focus" shot, which Harding said can come in handy as a sort of macro mode for close-range shots. But for those who are wondering, when shooting outside of Creative Mode and taking a full-wide shot (shooting with no zoom), the focus range of the Lytro goes from roughly 4 or 5 inches to infinity.

So how was it?

It's difficult to deny that the Lytro camera is a fascinating piece of technology, but after spending some time with it, I found that a certain amount of care needs to be taken when shooting photos in order to enjoy the benefits of light field photography. As Harding pointed out, shooting carelessly "is never going to yield an interesting picture. It's not a magic camera."

Lytro camera displayZooming was especially crucial for creating the necessary shallow depth of field, which, as Cheng explained, was very important in light field photography. If I was shooting at full wide angle, I found that only images with severely dramatic differences in depth -- like having my finger a matter of inches away from the lens with the rest of the scene behind it -- could produce notable shifts in focus when toying with them after the fact. If there were, say, two signs, one of which was four or five feet behind the other, but they were both 25 feet away from me, it was necessary for me to zoom in closer to achieve a better focus.

Also, with a screen that's less than 1.5 inches in size, I did not find the camera to be an ideal place to enjoy the spoils of light field photography. You could barely make out adjustments in focus -- again, unless it was something very dramatic like the finger example -- much less the finer details of a photo. Granted, you can double-tap the screen to zoom in and see the photo in better detail, but it's still not ideal as the resolution isn't that sharp and you have to drag your finger around to see other parts of the picture when you're zoomed in. It's all just a little claustrophobic, and that's the last thing I want when trying to explore something as remarkable as light field technology. But that's where the software and post-production come in.

Diving in deeper

After the other reporters had left, I stuck around to ask Mr. Cheng a few more questions about the camera, and to help answer some of them, he took out his computer to show me the Lytro software and some of the things that are possible with light field photography.

The setup of the Lytro software is pretty simple; it's very similar in setup to an iPhoto gallery. Once you click on one your uploaded images -- each of which are about 16 MB in size and in Lytro's custom format, .LFP (light field picture) -- it's maximized from a thumbnail to its full size and from there, you can click on different parts of the image to adjust the focus. Within the application, you can also tag photos for upload to Lytro's website (though they are compressed during this process, I was assured that no quality is lost). Not only can your photos be shared through Lytro's site, once your images are uploaded to Lytro's servers, you can share them all over the web (via email, Facebook, etc.) with the use of a Lytro embedded player, much like the one used to share YouTube videos. That way, anyone looking at your photos in the player won't need any sort of extra software, they can just click anywhere on the image to shift focus.

Lytro camera

But then Cheng showed me some other features of the software he had that will not be available at the time of launch, but may show up in software updates sometime down the road. And while it was a bit of a disappointment that consumers won't be able to enjoy some of the things I saw, it gave me a good idea of the potential behind light field photography.

For instance, Cheng mentioned that many of the people on the Lytro forums complain that the company is "dumbing down" the technology and, in some cases, believed that the camera was merely taking a handful of image slices -- say, 6 or 7 pictures with different focal points -- each time a photo was snapped (rather than each photo actually having an infinite range of focus beyond 4 or 5 inches). To disprove this claim, he pulled up a picture fiddled with a slider that was off to one side of the image. As his moved the slider up and down, the focus of the image moved further and further back (or forward, depending on which was he was moving the slider), showing that a continuous focus was, in fact, possible.

"Since you can refocus anywhere you want like this, you may find yourself coming across interesting reveals after you take a photo," said Cheng. "This kind of interaction is not something that's ever been possible."

He also showed me how the light field capture could also be used to create 3D effects, both with side-by-side split images and with a traditional anaglyph image. And if you aren't compelled to have sharp contrasts in focus in some of your photos, Cheng showed me how his software had an "all-focus" mode in which the entirety of a selected image would be put into focus (though he did note that if any of the subjects in the image could not be brought into focus in the first place, they would remain blurry when setting it to all-focus).

Lytro camera top and shutter buttonPerhaps most interesting, however, was when Cheng showed me something called a parallax shift, where he could actually look around an object from different angles within in photo, be it from above, below, or from the left or right. So in theory, if you took a photo of an object, you could actually use the parallax shift to look around the object and see what was behind it. Now, when Cheng showed it to me, he could only move very slightly in any given direction, and part of this is due to the fact that the lens of the Lytro is relatively small; the parallax shift is made possible due to the fact that the camera is capturing the light rays that are hitting the entire lens from all directions. So, the camera is capturing light all the way from the leftmost part of the lens to the rightmost, and from the top to the bottom, allowing you to view a subject from all those different angles.

"The camera is just the beginning of what is possible with light field photography," Cheng said.

And I agree with that. The Lytro camera is clearly just a start, because as impressive as it is, serious photographers will likely be dissatisfied with the quality of its images or its specs or hardware. The Lytro camera seems like more of a gateway, something to get people into light field photography and help them understand it before advancing the quality of the images. Because right now, when one of its pictures is flattened out and turned into a .JPEG or some other kind of typical picture file, its resolution is a mere 1080 x 1080, barely a megapixel. There's also the fact that the sensor is relatively small, and that pictures are taken with square proportions. Harding said that in the event that you decide to print any of your photos taken with the Lytro camera, the ideal size is 5" x 5". Perfect square images are a little odd, especially considering that most people are used to the proportions of a 4" x 6" photograph.

And one major drawback of the software is that, for reasons unbeknownst to me, it will only be available for Macs (with OS 10.6.6 or later) at the time of its launch. I get that a lot of serious and/or professional photographers use Macs for photo editing, but on the other hand, Mac users are in the minority compared to the sheer number of PC users. Not only are there plenty of photography enthusiasts who use PCs, there are also plenty of casual photographers -- or at least many people who are below the professional level -- who are also PC users and will subsequently be left out in the cold. Cheng did say, however, that a Windows version of the software is in development and will be released before the end of the year, though he did not give a specific timeframe.

Lytro has received no shortage of preorders for the camera; in fact, they're pretty backed up at the moment. I could not get an exact release date for the device, but Harding said that the first wave of cameras will be shipped out by the end of this month to those who first preordered the Lytro when it was unveiled late last year. But should you preorder a camera now, Harding estimated that you wouldn't receive it until sometime in May. As far as your choices go, the camera comes in three varieties: "graphite" and "electric blue" colors, both with 8 GB capacities, and "red hot", which has a 16 GB capacity. The 8 GB cameras can shoot 350 photos and are priced at $399, while the 16 GB camera can hold up to 750 pictures and goes for $499.